Arrangement for taking a CT scan and a SPECT scan of a patient in a single-pass diagnostic procedure. A SPECT scanner and a CT scanner are included. The SPECT scanner is mounted on a SPECT gantry and the CT scanner is mounted on a CT gantry. The SPECT and CT gantries are moveable with respect to one another between a mated operating configuration and a separated maintenance configuration. A pair of receiving brackets is fixedly mounted on the SPECT gantry. A pair of self-locating brackets is fixedly mounted on the CT gantry. Each of the pair of self-locating brackets is configured for assuming a prescribed position relative to a respective one of the pair of receiving brackets when in snug abutment together. A floating connection interconnects the CT scanner with the pair of self-locating brackets, and in this manner float-mounts the CT scanner with the SPECT scanner and facilitates the taking of the CT scan and a SPECT scan of a patient in a single-pass diagnostic procedure.